Crested Argus Rheinardia ocellata


Justification of Red List Category
This species is severely threatened by hunting throughout its range. Together with a reduction in the extent and quality of forested habitat within the range, this has likely led to a very rapid rate of population decline, which is projected to continue. The species is therefore classified as Endangered.

Population justification
The population size is preliminarily estimated to fall into the band 10,000-19,999 individuals. This equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals.

Trend justification
The scarcity or even lack of recent records from places where it used to be abundant previously (e.g. Bach Ma National Park, Ke Go Nature Reserve and Lo Xo Pass in Vietnam) indicate the rarity and local extinctions of this once common species. Yet, the population seems to persist in a few protected areas in Vietnam, like in the Bac Huong Hoa Nature Reserve (L.T. Trai in litt. 2018), the Ngoc Linh Nature Reserve (Vu Tien Thinh et al. 2017) and in the Khe Nuoc Trong Forest (D.L. Yong and L.T. Trai in litt. 2018), as well as the Khoun Xe Nong Ma Protected Area in Laos (Mayer 2017). High levels of snaring and habitat loss have been identified as the major threats to the species. 
There is no recent information about the population trend in Malaysia. This population is assumed to be much smaller than the one in Indochina; however, the recent discovery of a few individuals further north-east of the known population near the Taman Negara National Park (D.L. Yong in litt. 2018) indicates that the Malaysian population might be slightly larger than previously assumed. The fact that the Malaysian population occurs in higher altitudes than the Indochinese population might reduce the risk of hunting, as the level of snaring is generally lower in the highlands (J.W. Duckworth in litt. 2018).The overall rate of population decline is not known. However, given the high levels of hunting pressure over the last two decades on the larger population in Indochina while the smaller Malaysian population is presumably stable or even increasing, the rate of decline is precautionarily placed in the band 50-79% over three generations.

Distribution and population

Rheinardia ocellata is endemic to South-East Asia. The nominate subspecies R. o. ocellata occurs along the Annamite mountain chain in central and southern Vietnam and neighbouring eastern Laos, between the Nghe An province and the Da Lat Plateau in southern Vietnam. The subspecies R. o. nigrescens occurs in a narrow altitudinal band on the eastern flanks of the East Coast Range of Peninsular Malaysia within, or very close to, Taman Negara National Park.


In Laos and Vietnam, it is resident in primary and secondary evergreen forest from sea-level up to 1,500 m, and from 1,700-1,900 m on the Da Lat Plateau. It has been recorded from degraded forest habitats, including active logging concessions (N. Brickle in litt. 2004). It occurs at its highest densities in moist primary forest in lowlands up to c.900 m. In Malaysia, it inhabits tall hill dipterocarp/lower montane transitional forest, generally from c.800-1,100 m.


The Indochinese population is declining rapidly. Ongoing deforestation, both within and outside protected areas, decreases the amount of suitable habitat for the species; however, the rate of forest loss within its range over three generations (18 years) was estimated at only 5% (Tracewski et al. 2016). Therefore, deforestation is assumed to be only a minor contributor to the observed population decline. The most serious threat to the species stems from high levels of hunting, mostly via the use of snares. The species is hunted mainly for its meat, but also for the pet trade (McGowan and Kirwan 2018). Especially in the lowland forests throughout Vietnam and Laos, industrial snaring has been intensifying tremendously since the early 2000s (J.W. Duckworth in litt. 2018). Given that throughout the species's range, there are no measures in place to reduce the amount of snaring (J.W. Duckworth in litt. 2018), the population decline is very likely to go on, potentially even at an accelerating pace.
The Malaysian population is assumed to be less threatened, with the main documented threat being low levels of habitat loss in the periphery of Taman Negara National Park. However, its narrow altitudinal range lies mostly outside protected areas, which exposes the species to disturbance from logging (D. Wells in litt. 2005).

Conservation actions

Conservation Actions Underway
CITES Appendix I. It occurs in numerous protected areas, including Bach Ma National Park and at least 10 nature reserves in Vietnam, at least two designated and two proposed National Biodiversity Conservation Areas in Laos, and Taman Negara National Park in Malaysia.

Conservation Actions Proposed
Survey suitable habitat in Laos and Vietnam to clarify its current distribution and assess its abundance in relation to habitat degradation. Regularly monitor the Malaysian population and selected populations in Laos and Vietnam. Promote strict enforcement of hunting regulations in protected areas supporting populations, in combination with locally-targeted conservation awareness initiatives. Conduct taxonomic research into the relationship between the Malaysian and Indo-Chinese populations.


Male 190-239 cm, female 74-75 cm. Large pheasant with enormous tail. Male blackish-brown, peppered whitish all over. R. o. nigrescens has buff supercilium and throat and drooping, blackish-brown and white crest. R. o. ocellata has shorter, mostly brownish crest, white supercilium and throat, chestnut-brown foreneck, more numerous, smaller, buffier upperpart markings and more dark chestnut and grey on tail. Female is smaller, shorter-tailed and warm brown with blackish and buff bars, speckles and vermiculations. Somewhat paler below. Voice At dancing grounds, very loud woo'o-wao. Also series of far-carrying oowaaaa phrases.


Text account compilers
Hermes, C., Davidson, G., Keane, A., Mahood, S., Benstead, P., Martin, R., Taylor, J.

Trai, L., Eames, J.C., Yong, D., Duckworth, J.W., Wells, D., Brickle, N.

Recommended citation
BirdLife International (2021) Species factsheet: Rheinardia ocellata. Downloaded from http://www.birdlife.org on 27/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/10/2021.